A liquid crystal display (LCD) is a display of flat panel type commonly used at present, of which a thin film transistor liquid crystal display (TFT-LCD) is a mainstream product. With development of the LCD industry, LCD products with large size have gradually been a mainstream on market. However, an increase in size of the LCD may lead to an increase in resistance and capacitance of data lines and gate lines. Due to a problem of delay by the resistance and the capacitance, a phenomenon of afterimage may be occurred to a picture at time of shut down.
In the related arts, a power supply module with a reset function or an independent chip with a reset function are used to remove the afterimage phenomenon occurred to the picture of the LCD. These devices mainly detect an input voltage of the TFT-LCD. When the input voltage is less than a reference voltage inside the chip, a reset signal is outputted to a gate driving integrated circuit (IC), which pulls all of output voltages of the gate driving IC up to a gate ON voltage, thus the gates of the TFTs of corresponding pixels are turned on, and the function to remove the afterimage is realized.
However, the afterimage phenomenon basically exists in a time period subsequent to the OFF of a backlight source and prior to the OFF of the input signal. According to characteristics of a general product, only when at least 200 ms has been elapsed after the backlight source is turned off, will the input signal and then the input voltage be turned off. Therefore, for a method according to the related arts, the afterimage still may be occurred in 200 ms after the backlight source is turned off. Moreover, in the method according to the related arts, since the reset signal is outputted only when the input signal is detected to be decreased to a certain value, and at the same time, the input voltage is still in a threshold state in which the power supply module and the driving IC are operated and the fall time of the output voltage is from 0 to 10 ms generally (operation states of the power supply module and the gate driving IC are both in a threshold state), the pixel capacitance and the storage capacitance of the TFT-LCD can not be discharged rapidly, which fails to rapidly eliminate the afterimage.